CN113809988A - Method and device for testing solar cell and solar cell module based on short pulse width - Google Patents

Abstract

A method and a device for testing a solar cell and a solar cell module based on short pulse width belong to the field of solar cell testing and are characterized in that: voc, Isc and Pmax are obtained through a first IV curve test in a flash period, and an accurate Pmax value is further obtained through a second test after test parameters are adjusted. The test data acquisition in the Pmax core area in the second test is ensured to be in a stable period by presetting the second sampling delay equivalent multiplying power, the test process does not need manual intervention after the setting, and an accurate test result can be obtained by clicking once; the testing method does not depend on long pulse width to eliminate the capacitance effect in the testing process, can realize the aim of accurate testing in relatively short pulse width, has simple effect and is suitable for popularization and application.

Description

Method and device for testing solar cell and solar cell module based on short pulse width

Technical Field

The invention belongs to the field of solar cell testing, and particularly relates to a method and a device for testing a solar cell and a solar cell module based on short pulse width.

Background

With the development of the high-efficiency battery industrialized layout, the battery efficiency is higher and higher in the mass production of PERC, N-type TOP Con and HJT in the promotion stage, and the higher the battery efficiency is, the greater the difficulty in accurate testing is. Currently, industrial end testing of efficient solar cells and modules is based on two modes of electronic loads I-V and V-I, and long pulse width evaluation is matched with the Pmax relative difference value of the two tests to evaluate whether the test requirements are met. The laboratory and the third-party institution mostly adopt multiple 10ms subsection test fitting to obtain a complete IV curve. The N-type TOP Con and HJT have larger capacitance effect, relatively accurate electrical performance is obtained by using 10ms segmentation, and dozens or even hundreds of segmentation tests are required to meet the test requirements of the solar cell and the solar module.

Meanwhile, the industrial end solves the capacitance effect of a test object through long pulse width matched electronic load modulation to obtain more accurate electrical performance parameters, but the long pulse width needs good performance of test equipment, the total energy released by a light source in the long pulse width test process is larger, the partial loss of the light source and the power consumption of the equipment are more serious, the xenon lamp is adopted as the light source in most current solar simulators and is a consumable material, and for a client, the energy consumption and the practical cost brought by the long pulse width test are relatively more.

Disclosure of Invention

The invention aims to solve the problems and provides a method and a device for testing a solar cell and a solar cell module based on short pulse width, which can obtain a test result only by two times of tests without strictly depending on long pulse width.

In a first aspect, the present invention provides a method for testing solar cells and modules based on short pulse widths, comprising the steps of:

performing two IV curve tests in one flash period; the two IV curve tests are respectively a first IV curve test and a second IV curve test;

obtaining Voc, Isc and maximum power Pmax under the set test parameters through the first IV curve test; marking the voltage and the current corresponding to the maximum power Pmax as a point P according to the maximum power Pmax tested by the first IV curve;

the test parameters comprise a scanning area, sampling delay time and electronic load adjustment times;

adjusting test parameters;

adjusting the scanning area of the second IV curve test backward to 1% -15% of the scanning area in the first IV curve test by taking the point P as a starting point;

adjusting the electronic load adjusting times of the second IV curve test to be 0.1-10% of the electronic load adjusting times in the first IV curve test;

adjusting the sampling delay time of the second IV curve test according to a preset equivalent multiplying power, so that the sampling time in the second IV curve test process is in a stable period in the test period;

and performing a second IV curve test and outputting a test result.

Further, according to the method for testing the solar cell and the solar cell module based on the short pulse width, the sampling delay time of the second IV curve test is equal to the product of the preset equivalent multiplying power and the sampling delay time in the first IV curve test.

Further, the method for testing the solar cell and the solar cell module based on the short pulse width is characterized by comprising the following steps: the equivalent multiplying power ranges from 1 to 10000 times; the selection of the equivalent magnification is related to the tested pulse width; the adopted equivalent multiplying power enables the whole acquisition system to enter a stable period after the corresponding electronic load is adjusted and delayed in the process of measuring the maximum power, and the capacitance effect is eliminated after the whole acquisition system enters the stable period, so that the accuracy of the test can be met.

Further, according to the method for testing the solar cell and the solar cell module based on the short pulse width, the electronic load adjustment times in the first IV curve test are 10-2000; the balance of the test is broken by adjusting the electronic load once, and the corresponding curve can be drawn by adjusting the electronic load for corresponding times in the process from short circuit to open circuit, otherwise, the curve is easy to distort.

In a second aspect, the invention provides a device for testing solar cells and solar modules based on short pulse width, which comprises a testing module, an adjusting module and an output module which are connected in sequence;

the testing module is used for testing the solar cell and the solar cell module according to the set testing parameters;

the adjusting module is used for adjusting the second test parameters according to the first test parameters;

the output module is used for outputting the test result of the test module.

Further, according to the device for testing the solar cell and the solar cell module based on the short pulse width, the adjustment of the second test parameter specifically comprises: adjusting the scanning area of the second IV curve test backward to 1% -15% of the scanning area in the first IV curve test by taking the point P as a starting point;

adjusting the electronic load adjusting times of the second IV curve test to be 0.1-10% of the electronic load adjusting times in the first IV curve test;

and adjusting the sampling delay time of the second IV curve test according to a preset equivalent multiplying factor, so that the sampling time in the second IV curve test process is in a stable period in the test period.

According to the method and the device for testing the solar cell and the solar cell module based on the short pulse width, Voc, Isc and Pmax are obtained through a first IV curve test in a flash period, and an accurate Pmax value is further obtained through a second test after test parameters are adjusted. The test data acquisition in the Pmax core area in the second test is ensured to be in a stable period by presetting the second sampling delay equivalent multiplying power, the test process does not need manual intervention after the setting, and an accurate test result can be obtained by clicking once; the testing method does not depend on long pulse width to eliminate the capacitance effect in the testing process, can realize the aim of accurate testing in relatively short pulse width, has simple effect and is suitable for popularization and application.

Drawings

FIG. 1 is a schematic diagram of electrical parameters in a short pulse width-based solar cell and device testing process according to an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a solar cell and device testing apparatus based on short pulse width testing according to a third embodiment of the present invention;

wherein 1-irradiance line, 2-voltage loop signal, 3-current loop signal.

Detailed Description

The method and apparatus for testing solar cells and modules based on short pulse width according to the present invention will be described in detail below with reference to the accompanying drawings and examples.

Example one

In the disclosed example, the light source adopts a xenon lamp, taking an I-V mode as an example, the electric parameters such as irradiance, voltage, current and the like in the test process are represented as shown in fig. 1, wherein a line 1 is an irradiance line and represents the energy output state of the xenon lamp; line 2 is a voltage loop signal of the object to be measured; line 3 is the current loop signal of the object to be measured. After the xenon lamp is triggered, the xenon lamp output light energy is modulated by a PID negative feedback circuit to enter a stable output state, and data acquisition is carried out in an output stable time period after preset time delay. Since the electronic load is in an open circuit state, the tested voltage is Voc, and the test loop off current is zero. When the electronic load is modulated by control and adjusted from an open circuit state to a short circuit state, after time delay, the voltage is zero as shown by a line 2 and a line 3, and the current tested at the moment is the short circuit current Isc. After entering the IV test stage, the line 1 keeps stable output; the electronic load is adjusted from a short-circuit state to an open circuit, i.e. the external impedance in the test circuit (the electronic load equivalent can be understood as a sliding rheostat) is gradually increased from zero to infinity. After each modulation of the corresponding electronic load, the state of the test loop enters the stable period after the delay time and then data acquisition is performed, as can be seen from fig. 1, the long time is the unstable period at the front end after each adjustment of the electronic load, and thus the data acquisition is unstable, and the acquisition accuracy cannot be ensured.

The method for testing the solar cell and the solar cell module based on the short pulse width comprises the steps of carrying out two times of IV curve tests in one flash period; the two IV curve tests are respectively a first IV curve test and a second IV curve test.

The method specifically comprises the following steps:

step one, obtaining Voc, Isc and maximum power Pmax under the set test parameters through the first IV curve test; marking the voltage and the current corresponding to the maximum power Pmax as a point P according to the maximum power Pmax tested by the first IV curve; the test parameters comprise a scanning area, sampling delay time and electronic load adjustment times.

Step two, adjusting test parameters; adjusting the scanning area of the second IV curve test backward to 8% of the scanning area in the first IV curve test by taking the point P as a starting point; adjusting the electronic load adjustment times of the second IV curve test to be 5% of the electronic load adjustment times in the first IV curve test, wherein the electronic load adjustment times in the first test in the embodiment of the disclosure are 400; adjusting the sampling delay time of the second IV curve test according to a preset equivalent multiplying power, wherein the sampling delay time of the second IV curve test is equal to the product of the preset equivalent multiplying power and the sampling delay time in the first IV curve test; the sampling time during the second IV curve test is made to be in the stable phase within the test period.

And step three, performing a second IV curve test and outputting a test result.

In the process of testing the IV curve for the first time, determining a starting point according to the maximum value of Pmax obtained for the first time, and adjusting the scanning interval backwards; because the sampling delay in the first test data acquisition is not long enough, the test data is different from the actual data because the test data does not enter the stabilization period.

The sampling interval time is set in specific application by setting equivalent multiplying power through an upper computer, and a specific test object usually has relative test pulse width, so that the problem of sufficient delay of data acquisition in the second IV curve test process can be solved by correspondingly setting the equivalent multiplying power, and the acquisition is ensured to be in a stable period. In the embodiment of the present disclosure, the pulse width is selected to be 20ms, and the number of sampling points in the first IV curve test is set to be 400 points, so that the total time between corresponding points is 0.05ms, and the 0.05ms includes the sampling delay time and the data acquisition time. Equivalent multiplying power corresponding to a test object is set through an upper computer, the pulse width time required by the first IV curve test is 20ms, the Voc test time is usually within 10ms, and the corresponding acquisition delay time is 0.044 ms; the equivalent multiplying factor multiplied by 0.044ms is the total sampling delay time in the second IV curve test. By the method, data acquisition can be ensured to be in a stable period by adjusting the equivalent multiplying power in the second IV curve test.

Example two

In the embodiment of the present disclosure, taking an HJT device to be tested as an example, taking an I-V mode as an example, the number of points is 400 points for the first scanning, the pulse width is selected to be 10ms, the corresponding points of Voc, Isc, and Pmax and the interval of the second scanning are obtained for the first scanning, the testing process is continuous in one illumination period, and the testing interval is not interrupted during the testing process; the second scanning interval is 9% of the total sampling interval of the first Pmax corresponding point backward adjustment, and the number of the electronic load adjustment integers in the scanning interval is set to be 7. The sampling delay is set to be equivalent multiplying power through the upper computer, and relatively accurate test data can be obtained by setting the equivalent multiplying power to be 150 in the embodiment of the disclosure because the capacitance effect of the tested object is large.

The Voc and the Isc are obtained for the first time, and the Pmax is obtained for the second time, so that the accurate electrical property parameters of the measured object can be quickly and efficiently obtained through the scheme.

EXAMPLE III

In the embodiment of the present disclosure, as shown in fig. 2, an apparatus for testing a solar cell and a solar module based on short pulse width is provided, which includes a testing module, an adjusting module and an output module connected in sequence; the testing module is used for testing the solar cell and the solar cell module according to the set testing parameters; the adjusting module is used for adjusting the second test parameters according to the first test parameters; the output module is used for outputting the test result of the test module.

The adjustment of the second test parameter during the test execution specifically includes: adjusting the scanning area of the second IV curve test backward to 1% -15% of the scanning area in the first IV curve test by taking the point P as a starting point; adjusting the electronic load adjusting times of the second IV curve test to be 0.1-10% of the electronic load adjusting times in the first IV curve test; and adjusting the sampling delay time of the second IV curve test according to a preset equivalent multiplying factor, so that the sampling time in the second IV curve test process is in a stable period in the test period.

The method for testing the solar cell and the solar cell module based on the device for testing the solar cell and the solar cell module based on the short pulse width in the embodiment of the disclosure is the same as the method in the first embodiment and the second embodiment, and is not repeated herein.

The scheme of the invention is not limited to a linear electronic load mode, and is also applicable to nonlinear and other modes of electronic load modulation modes; meanwhile, the scheme of the invention does not solely depend on the pulse width to solve the capacitance effect of the measured object.

According to the scheme and the thought of the invention, engineering technicians in the field can develop related matched test schemes under the guidance of the thought.

Claims (6)

1. A method for testing solar cells and components based on short pulse widths is characterized in that:

performing two IV curve tests in one flash period; the two IV curve tests are respectively a first IV curve test and a second IV curve test;

obtaining Voc, Isc and maximum power Pmax under the set test parameters through the first IV curve test; marking the voltage and the current corresponding to the maximum power Pmax as a point P according to the maximum power Pmax tested by the first IV curve;

the test parameters comprise a scanning area, sampling delay time and electronic load adjustment times;

adjusting test parameters;

adjusting the scanning area of the second IV curve test backward to 1% -15% of the scanning area in the first IV curve test by taking the point P as a starting point;

adjusting the electronic load adjusting times of the second IV curve test to be 0.1-10% of the electronic load adjusting times in the first IV curve test;

adjusting the sampling delay time of the second IV curve test according to a preset equivalent multiplying power, so that the sampling time in the second IV curve test process is in a stable period in the test period;

and performing a second IV curve test and outputting a test result.

2. The method for testing solar cells and modules based on short pulse widths of claim 1, wherein: and the sampling delay time of the second IV curve test is equal to the product of the preset equivalent multiplying power and the sampling delay time in the first IV curve test.

3. The method for testing solar cells and modules based on short pulse widths according to claim 1 or 2, wherein: the equivalent multiplying power ranges from 1 to 10000 times.

4. The method for testing solar cells and modules based on short pulse widths of claim 3, wherein: the number of times of electronic load adjustment in the first IV curve test is 10-2000.

5. An apparatus for testing solar cells and modules based on short pulse widths, comprising: the device comprises a test module, an adjustment module and an output module which are connected in sequence;

the testing module is used for testing the solar cell and the solar cell module according to the set testing parameters;

the adjusting module is used for adjusting the second test parameters according to the first test parameters;

the output module is used for outputting the test result of the test module.

6. The apparatus for testing solar cells and modules based on short pulse widths of claim 5, wherein: the adjustment of the second test parameter specifically comprises the following steps: adjusting the scanning area of the second IV curve test backward to 1% -15% of the scanning area in the first IV curve test by taking the point P as a starting point;

adjusting the electronic load adjusting times of the second IV curve test to be 0.1-10% of the electronic load adjusting times in the first IV curve test;

and adjusting the sampling delay time of the second IV curve test according to a preset equivalent multiplying factor, so that the sampling time in the second IV curve test process is in a stable period in the test period.

Images